Throughout industry, it is found necessary to connect or otherwise fasten flexible tubing to rigid components to make hook-ups for the transfer of liquids and gases or to complete an assembly with a termination or plug. This has been accomplished by utilizing various configurations, depending upon the permanence and security of the connection desired.
Temporary connections usually can be made by sliding the flexible tubing over a smooth walled rigid component or tube with the component outside diameter slightly larger than the tube inside diameter, relying upon the dimensional interference of the two mating parts to stretch the flexible tube radially. The resilience of the tube then provides a gas or liquid tight seal while still providing the ability to separate and reconnect the parts with relative ease. Typically, this type of connection will disconnect with a minimal longitudinal pulling force on the tubing.
Consequently, in order to provide for more secure connections or permanent connections various additional design features were developed to enhance the security of the connection. Often, the rigid component will utilize a barbed, threaded, ribbed, textured, etc., configuration for a mechanical interference or "bite" between the inner wall of the flexible tube and the outer surface of the rigid part. Such a connection makes separation of the two parts much more difficult, and for total security the tubing can be clamped or bonded to the rigid component.
These methods of making tubing connections to rigid connectors are common in the medical industry, utilizing flexible tubing fabricated of polyethylene, vinyl, polyurethane or latex.
However, with the rapidly increasing usage of flexible silicone rubber tubing, particularly unique problems occur when making a connection between the silicone tubing and a rigid connector. Because of the extremely elastic nature of the material combined with the lubricity of the surface of the material, it has been found that connections made with barbed connectors, threaded connectors, etc., are not secure and are apt to separate when subjected to relatively small tensile stresses. In order to provide secure connections between silicone tubing and other rigid components, these connections are normally bonded with additional silicone adhesive, resulting in a permenent connection, which is expensive, labor consuming and unsightly. Additionally, the only method of separating the silicone tube from such a bonded joint is by cutting the tube from the connector, making the rigid connector unsuitable for reconnection because of the portion of tubing and adhesive remaining on the connector.